Grippers for a heel lasting machine



Sept. 20, 1966 H. SCHINDLER GRIPPERS FOR A HEEL LASTING MACHINE 2 Sheets-Sheet 1 Filed Aug. 16, 1965 VIIIIIIIIIIIIIIII Se t. 20, 1966 H. SCHINDLER GRIPPERS FOR A HEEL LASTING MACHINE Filed Aug. 16, 1965 2 Sheets-Sheet 2 United States Patent 3 273,183 GRIPPERS FOR A I-lEEL LASTING MACHINE Herbert Schindler, Wagenstrasse 38, Pirmasens, Germany Filed Aug. 16, 1965, Ser. No. 479,941 Claims priority, application Germany, Aug. 17, 1964, Sch 35,634 Claims. (Cl. 1211.3)

This invention relates to gripping devices for a heel lasting machine having grippers which act on the upper at the tip of the shoe and pull the same against the heel portion of the last for the purpose of shaping.

There are two processes for wiping a shoe upper over a last. In the commonly used process, the shoe is overhauled and is then wiped at the tip; in modern lasting machines, the shoe is simultaneously overhauled in a machine and is then wiped at the tip either to the ball or including the ball. Subsequently, the heel is wiped, either with tacks or else with heel lasting machines.

More recently, a method has been adopted to preform the uppers prior to the overhauling or prior to the wiping of the heel, so that the leather in the heel portion takes on the approximate shape of the last prior to the wiping, in order to facilitate the subsequent overhauling and wiping process. For this purpose the uppers are shaped over heated metallic molds which correspond to the heel portion of the wiping lasts, in machines which are operated by foot or hydraulically, in that they are first stretched by one or more grippers and their heel portion is then pressed against the heated mold by a heel band or an elastic pad.

Recently there have been machines with which the shoe is wiped starting from its heel portion. These machines operate either with metallic molds over which the upper leather is molded, as described above, but with simultaneous turning down of the upper leather wiping tuck and simultaneous gluing of said Wiping tuck against an insole fixed on the meallic mold. However, this method has the considerable disadvantage that the wiping last can be put into the preformed uppers only after said operation has been completed and that this will again cause a deformation of the heel portion; and it has the additional disadvantage that very many metallic molds are required.

Another known method uses the original wiping last. However, this method uses thermoplastic back flaps which are activated by hot air prior to the wiping process. The upper is pulled forwardly and the heel portion is thereby pressed against the last, but no unobjectionable transitions to the not yet fixed articulated part will form during the wiping of the upper leather, i.e., during the turning down of the wiping tuck and the simultaneous gluing of the insole, since the upper leather extends upwardly in the articulated portion at right angles to the bottom of the last during the wiping process in the heel portion.

It is an object of the present invention to impart the final shape to uppers in the articulated portion and in the heel portion prior to the start of the wiping process.

The invention solves this problem in that, on the ends of a shaft which is positioned in the machine transversely beyond the heel portion of the last, grippers are positioned horizontally to the bottom of the last and extending against each other toward the center of the last on swinging arms for gripping the uppers at the height of the shoe articulation; the jaws of said grippers being closed by a hydraulic cylinder and being moved, in closed state, jointly toward the center of the last.

According to an embodiment of the invention, the shaft is driven by an angle arm (elbow) which acts on the center of the shaft. For this purpose, the angle arm may be driven by another hydraulic cylinder arranged on 3,273,183 Patented Sept. 20, 1966 the machine. For a purpose which will be explained later, an oblong hole is provided in the hub of the arms, a driver which is connected to the shaft engaging in said oblong hole. This has the result that the swinging motion of the arms starts somewhat later than the swinging motion of the angle arm. According to the invention, grippers are so developed that a housing is fixed to the arm which contains the hydraulic cylinder and the piston with the lower jaw of the grippers and which guides the upper jaw, said upper jaw being supported by abutting against a stop of the housing by way of a compression spring, and said upper jaw comprising a lug which runs up the last with an inclined surface.

For simultaneously holding an insole, the angle arm may carry an adjustable thrust member which is directed toward the surface of the heel portion of the last.

An embodiment of the invention is illustrated in the accompanying drawing, in which:

FIGURE 1 is a front view of the device;

FIGURE 2 is a top view of the-device; and

FIGURE 3 is an end view of the device.

Referring now to the drawings, element 1 is a last carrier, element 2 is a lock nut, element 3 is the last, the upper 4 being put over said last. Plane 19 is the center plane of the last 3 which comprises a heel portion 3', an articulated portion 3" and a bottom 3".

A hydraulic cylinder 5 drives an angle lever 7 pivotable about shaft 6, which is positioned in the machine. An adjustable thrust transmitting member 8 is fixed to one end of the angle lever.

Arms 16 are arranged at the ends of the shaft 6. Their hubs are provided with slots :15, in which engage pins 20, which are firmly connected to the shaft 6. When the hydraulic cylinder 5 drives the angle lever 7, the latter drives the shaft 6 and, with a moment of delay caused by the coupling between the slot 15 and the pin 20, the arms 16 as well. Owing to this arrangement, an insole which is placed on the upper side of the last 3 is first pressed on by the thrust member 8, before the grippers 17 start to operate.

The grippers 17 and the housing 21 which carries them are fixed to the free ends of the arms 16 by means of a clamp 9.

The grippers consist of a lower jaw 11 and an upper jaw 10. The upper jaw 10 is supported by a stop or abutment 13 of the housing 21 by way of the compression spring 12. At its rear, the jaw 10 has a slot 14 which terminates the horizontal motion of the jaw 10 when moving against the stop 13.

The housing 21 contains a hydraulic cylinder 22; a piston 18, which is connected to the lower jaw 11 of the grippers 17, moves in said cylinder.

The last carrier '1 can be adjusted by the knurled nut 2 and receives the last 3 which is to be worked, as well as the upper 4 put over said last.

By means of a known device (not shown) the upper 4 is gripped by one or more grippers and pulled forwardly, so that the heel portion also firmly engages the last 3. A heel band (not shown), which consists of plastic material, or an air cushion, or of a rubber-like yielding material, then engages and presses the upper 4 from the outside against the last 3.

The articulated grippers 17 according to the invention then swing into the operating range of the articulated portion 3", due to the fact that oil-operated or pneumatic cylinder 5 actuates angle lever 7 fixed by shaft 6 to the machine. At its front end, the angle lever 7 carries adjustable stop 8 which is placed on the insole in the heel region 3'. At its outer ends, the shaft 6 carries the two articulated grippers systems 16, 17, 21. These systems consist of the arms 16, which carry the housing 21 with the grippers 17. When the angle lever 7, which is connected to the shaft 6, is actuated, said gripper systems 16, 17, 21 swing into their operating range. The grippers 17 are adjustable in several directions with respect to the last 3 by the clamp 9, which is set in such a manner that, after the gripper systems 16, 17, 21 have swung into their operating range, the upper half of the grippers or the jaw lies with its tip 10' on the insole and that the leather extending upwardly in the articulated portion, projects between the jaw 10 and the lower jaw 11.' The closing motion of the grippers 17 takes place pneumatically or hydraulically by way of the piston which is firmly conncted to the lower jaw 11. More particularly, when the closing motion of the grippers starts, the piston 18, and hence the lower jaw 11, moves towards the last 3 and clamps the upper leather which is in the mouth of the grippers.

The upper jaw 10 is acted on by the compression spring 12 which abuts against projection 13 of the housing 21. The closing motion of the lower jaw 11 against the upper jaw 10 causes the compression of said compression spring 12, so that the closed grippers are able to continue to move toward the central plane 19 of the last 3.

The path of the grippers is limited by the stop 13 which extends into the oblong hole 14 of the upper jaw 10, as aforesaid. The upper jaw 10 is so developed that it comprises an inclined surface 10 following the tip 10' of the grippers. Owing to the motion of the jaw 10 towards the center 19 of the last, the inclined surface 10' impinges on the edge of the last and slides with said surface along the .edge of the last, thereby causing the entire gripper system 16, 17, 21 to rise and to rotate about the shaft 6. Rotation of the shaft 6 is made possible by the slot 15. The guided lifting of the gripper causes a certain pull on the uppers 4 in the articulated region 3", while it is simultaneously moved along the longitudinal axis of the last.

After the upper leather has been pushed toward the axis of the last in the above-described manner, the heel wipers are actuated and the upper leather in the heel region is turned inwardly, is glued and pressed What is claimed is:

1. Apparatus comprising means for supporting a last having an upper surface adapted to support an insole and having sides along which extends uppers constituting, with said insole, part of a shoe, said means having a center plane, gripping means on opposite sides of the last and including relatively movable members adapted to clamp the uppers on opposite sides of the last and generally at the level of said upper surface, means to actuate the gripping means to engage the uppers between said members and to move the gripping means towards said center plane to wipe said uppers over said last, a thrust device for holding the insole against said last, means coupling said device and said gripping means for cooperative movement, said means for actuating the gripping means including a shaft supporting said gripping means, an angle arm coupled to said shaft to rotate the same and change the position of the gripping means relative to the upper surface of the last, and piston and cylinder elements coupled to one of the members of each gripping means to control the clamping of the uppers, said thrust device being mounted on, said angle arm, arms mounted on said shaft and supporting said gripping means, and lost motion connection means between said arms and shaft whereby the thrust device is moved by said angle arm before the gripping means is moved, each said gripping means including a spring between said members and against which the associated piston and cylinder elements operate, at least one member of each gripping means having an inclined surface adapted to ride up over the last.

. 4 2. Apparatus as claimed in claim 1, wherein the lost motion connection means is' a pin and slot connection.

3. Apparatus as claimed in claim 1, comprising clamp means adjustably mounting the pincers on said shaft.

4. A gripper mechanism for a lasting machine having a last disposed with its bottom facing-upwardly, said mechanism comprising a pair of spaced arms, gripper means mounted on each said arm, each gripper means comprising an upper and lower jaw which are relatively movable and which have an initial position in spaced relation, a rotatable shaft supporting said arms, drive means for rotating said shaft to Cause the arms to move in a direction towards the last bottom and bring the upper jaws into engagement therewith while an upper placed on said last projects between the jaws, a follower arm secured to said shaft and including insole pressing means and means for relatively moving the jaws of each gripper means towards one another to clamp the upper therebetween while moving both gripper means towards one another.

5. A gripper mechanism as claimed in claim 4, wherein said means for relatively moving the jaws of each gripper means comprises driving means at either side of the shaft extending parallel to the upper jaws and in engagement with the lower jaws for displacing the same towards the respective upper jaws.

6. A gripper mechanism as claimed in claim 5, comprising means slidably supporting the upper jaws for move ment parallel to said shaft, said upper jaws being displaced by the lower jaws when the latter are displaced and the upper and lower jaws grip an upper, and springs engaging the upper jaws to resist displacement thereof and return the upper jaws to initial position.

7. A gripper mechanism as claimed in claim 6, wherein said means slidably supporting the upper jaws comprises a housing, said respective driving means comprising pistons slidably mounted in respective housings and connected to an associated lower jaw, an abutment in each housing for engaging an associated upper jaw in its initial position, said springs being positioned between the abutments and the associated upper jaws in a blind bore thereof on a side of said abutments remote from the last.

8. A gripper mechanism as claimed in claim 5, wherein said upper jaws each have a lower face, with a sloping portion for contacting an edge of the last whereby as said jaws of the gripper means are moved towards one another the gripper means and arms are caused to rotate about said shaft.

9. A gripper mechanism as claimed in claim 4, comprising lost motion connection means between said arms and shaft whereby the follower arm is moved by the shaft before the gripping means is moved by the arms.

10. A gripper mechanism as claimed in claim 4, comprising clamp means adjustably mounting the gripping means on the shaft,

References Cited by the Examiner UNITED STATES PATENTS 502,507 8/1893 Whifien et al 1214.5 1,197,438 9/1916 Brock 1210.5 1,267,370 5/1918 Brock 1210.5 1,344,316 6/1920 Pym 129 1,723,342 8/1929 Fernald 129 2,706,823 4/1955 Jorgensen 12--l0.1 3,008,157 11/1961 Weinschenk 12-14.5 X

JORDAN FRANKLIN, Primary Examiner,

PATRICK D, Examiner. 

1. APPARATUS COMPRISING MEANS FOR SUPPORTING A LAST HAVING AN UPPER SURFACE ADAPTED TO SUPPORT AN INSOLE AND HAVING SIDES ALONG WHICH EXTENDS UPPER CONSTITUTING, WITH SAID INSOLE, PART OF A SHOE, SAID MEANS HAVING A CENTER PLANE, GRIPPING MEANS ON OPPOSITE SIDES OF THE LAST AND INCLUDING RELATIVELY MOVABLE MEMBERS ADAPTED TO CLAMP THE UPPER ON OPPOSITE SIDES OF THE LAST AND GENERALLY AT THE LEVEL OF SAID UPPER SURFACE, MEANS TO ACTUATE THE GRIPPING MEANS TO ENGAGE THE UPPERS BETWEEN SAID MEMBERS AND TO MOVE THE GRIPPING MEANS TOWARDS SAID CENTER PLANE TO WIPE SAID UPPERS OVER SAID LAST, A THRUST DEVICE FOR HOLDING THE INSOLE AGAINST SAID LAST, MEANS COUPLING SAID DEVICE AND SAID GRIPPING MEANS FOR COOPERATIVE MOVEMENT, SAID MEANS FOR ACTUATING THE GRIPPING MEANS INCLUDING A SHAFT SUPPORTING SAID GRIPPING MEANS, AN ANGLE ARM COUPLED TO SAID SHAFT TO ROTATE THE SAME AND CHANGE THE POSITION OF THE GRIPPING MEANS RELATIVE TO THE UPPER SURFACE OF THE LAST, AND PISTON AND CYLINDER ELEMENTS COUPLED TO ONE OF THE MEMBERS OF EACH GRIPPING MEANS TO CONTROL THE CLAMPING OF THE UPPERS, SAID THRUST DEVICE BEING MOUNTED ON SAID ANGLE ARM, ARMS MOUNTED ON SAID SHAFT AND SUPPORTING SAID GRIPPING MEANS, AND LOST MOTION CONNECTION MEANS BETWEEN SAID ARMS AND SHAFT WHEREBY THE THRUST DEVICE IS MOVED BY SAID ANGLE ARM BEFORE THE GRIPPING MEANS IS MOVED, EACH SAID GRIPPING MEANS INCLUDING A SPRING BETWEEN SAID MEMBERS AND AGAINST WHICH THE ASSOCIATED PISTON AND CYLINDER ELEMENTS OPERATE, AT LEAST ONE MEMBER OF EACH GRIPPING MEANS HAVING AN INCLINED SURFACE ADAPTED TO RIDE UP OVER THE LAST. 